CyberSecBulletin
CVE-2026-56422NVD status: Awaiting Analysis

misp: Authorization Bypass Through User-Controlled Key

Published Updated By the CyberSecBulletin desk

CVE-2026-56422 is a critical-severity authorization bypass through user-controlled key vulnerability in misp, with a CVSS 4.0 base score of 9.4 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected misp versions: 2.5.41 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of misp you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
MISPmisp2.5.41 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
HighSerious loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
HighSerious loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
HighSerious loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA.

Official description

Multiple MISP core controllers and model capture paths accepted client-controlled request fields such as primary keys (id) and ownership/scope foreign keys (event_id, org_id, user_id, sharing_group_id, galaxy_cluster_uuid, organisation_uuid, and related nested object identifiers) without consistently stripping, pinning, or revalidating them against the server-authorized object. In affected paths, an authenticated user with access to one authorized object could submit crafted REST or form payloads that caused MISP to save data against a different object than the one checked by the authorization logic. Depending on the endpoint, this could allow object overwrite, object re-parenting, ownership transfer, unauthorized sharing-group scoping, event/object injection, proposal retargeting, or stored attacker-controlled content appearing in another user’s context. The fixes harden affected create/edit/import flows by stripping client-supplied primary keys on create-only saves, re-pinning route- or database-authorized identifiers before save operations, validating effective sharing-group scope, and adding field whitelists where ownership fields must never be editable. The initial broad fix also added a central CRUDComponent::edit() primary-key re-pin so payload-supplied IDs cannot redirect saves away from the already-authorized row. GitHub’s patch for 7acf8220c describes this central issue as CRUDComponent::edit() copying supplied fields, including a payload primary key, onto the loaded record, allowing CakePHP save() to update an arbitrary row unless the loaded ID is re-pinned.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

How developers prevent this class of flaw

  • For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
  • Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
  • Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.

More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).

References

Patches and release notes

Other vulnerabilities in misp

All misp vulnerabilities

Recent Authorization Bypass Through User-Controlled Key vulnerabilities

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